As we studied yesterday, our toaster oven has 3 main controllers: temperature, function and timer/toaster. Among these 3 controller boxes, the function controller is the most complex and requires some further studies. I took a picture of the backside of the function controller and here is what it looks like:

After that, I created a simple diagram representing this function controller. It has a total of 6 ports, which I denoted A, B, C, D, E, F respectively from left to right and from up to down. The detailed notations for the ports are shown below:

Function Diagram: Port Notation

Then, for each of the four functioning modes (keep warm, bake, broil, toast), I check for the connections between the ports using the multimeter.

Multimeter

The multimeter can be used to measure different elements within a circuit such as voltage, current, resistance. I changed this multimeter to measure the resistance to check if there is a connection between any two ports. If there is a short circuit then the number on the screen will get close to 0, indicating 0 resistance. On the other hand, if it is a open circuit, or no connection, then it’ll show the number 1. Any number other than 0 and 1 will show that there is a connection between the two ports and the magnitude of the number is the total resistance going from one port to the other.

Thus, with 4 modes, I made 4 different tables of size 7×7. The results are shown below:

Keep warm

Bake

Broil

Toast